The increasing number of parts variants on an assembly line requires an improvement for a cost efficient and flexible parts supply system. For that reason, the Set Parts Supply (SPS) system was introduced by Toyota as a new material handling system for supplying parts in sets based on the kitting concept. In this study, we investigate the consideration of design concepts in SPS implementation at one of Malaysia’s automotive manufacturers through a case study in a mixed-model assembly line that contains many parts to be assembled to the car body. From our case study, we found that the design of the ‘parts only’ or minomi concept on the component racks contributes to the elimination of waste; mura, muri and muda. Finally, we present the lean approach in the minomi concepts that used in designing the component racks.